<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>

</body>
<script type="text/javascript">
var a = 1;
var b = 2;
// 根据上面两个变量，运用变量的赋值或计算，得出a=2;b=1
var t;
t = a;
a = b;
b = t;
console.log(a);
console.log(b);
</script>
</html>